# NetworkX 2.1¶

Release date: 22 January 2018

Supports Python 2.7, 3.4, 3.5, and 3.6.

NetworkX is a Python package for the creation, manipulation, and study of the structure, dynamics, and functions of complex networks.

For more information, please visit our website and our gallery of examples. Please send comments and questions to the networkx-discuss mailing list.

## Highlights¶

This release is the result of four months of work with 75 pull requests by 37 contributors. Highlights include:

Arrows for drawing DiGraph edges are vastly improved! And an example to show them.

More than 12 new functions for graph generation, manipulation and/or new graph algorithms.

Add a large clique size heuristic function (#2830)

Add rooted product function (#2825)

Label Propagation Community Detection (#2821)

Minimum cycle basis (#2823)

Add Mycielski Operator (#2785)

Adds prefix_tree, dag_to_branching, and example. (#2784)

Add inverse_line_graph generator from #2241 (#2782)

Steiner tree and metric closure. (#2252)

Add flow based node and edge disjoint paths. (#2063)

Update geometric networks with new models (#2498)

Graph edit distance (#2729)

Added function for finding a k-edge-augmentation (#2572)

G.name is no longer processed by graph operators. It remains as a property mechanism to access

`G.graph['name']`

but the user is in charge of updating or changing it for copies, subgraphs, unions and other graph operations.

## Improvements¶

Many bug fixes, documentation changes.

Speed improvements especially for subgraphs.

Changed input variable names for functions using

`**kwds`

to avoid name collisions – especially`add_node`

New examples for arrows and spectral embedding of the grid graph.

## API Changes¶

[#2498] In

`geographical_threshold_graph`

, starting in NetworkX 2.1 the parameter`alpha`

is deprecated and replaced with the customizable`p_dist`

function parameter, which defaults to r^-2 if`p_dist`

is not supplied. To reproduce networks of earlier NetworkX versions, a custom function needs to be defined and passed as the`p_dist`

parameter. For example, if the parameter`alpha`

= 2 was used in NetworkX 2.0, the custom function def custom_dist(r): r**-2 can be passed in versions >=2.1 as the parameter p_dist = custom_dist to produce an equivalent network. Note the change in sign from +2 to -2 in this parameter change.[#2554] New algorithms for finding k-edge-connected components and k-edge-connected subgraphs in directed and undirected graphs. Efficient implementations are provided for the special case of k=1 and k=2. The new functionality is provided by:

`k_edge_components()`

`k_edge_subgraphs()`

[#2572] New algorithm finding for finding k-edge-augmentations in undirected graphs. Efficient implementations are provided for the special case of k=1 and k=2. New functionality is provided by:

`k_edge_augmentation()`

[#2812] Removed

`bellman_ford`

, please use`bellman_ford_predecessor_and_distance`

.[#2811] Removed

`to_pandas_dataframe`

and`from_pandas_dataframe`

, please use`to_pandas_adjacency`

,`from_pandas_adjacency`

,`to_pandas_edgelist`

, or`from_pandas_edgelist`

.[#2766] Add seed keyword argument to random_layout and spring_layout

[#2776] Add threshold option to spring layout

[#2774] max_weight_matching returns set of edges

[#2753] Add directed graphs support for jit_graph reading

[#2788] Control node-border color in draw_networkx_nodes

## Deprecations¶

[#2819] Deprecate

`connected_component_subgraphs`

,`biconnected_component_subgraphs`

,`attracting_component_subgraphs`

,`strongly_connected_component_subgraphs`

,`weakly_connected_component_subgraphs`

. Instead use:`[G.subgraph(c) for c in *_components]`

## Contributors¶

Jack Amadeo

Boskovits

Daniel Bradburn

David Bradway

Ariel Chinn

Jon Crall

Rodrigo Dorantes-Gilardi

Bradley Ellert

Adam Erispaha

Ioannis Filippidis

ForFer

Louis Gatin

Aric Hagberg

Harry

Huston Hedinger

Charles Tapley Hoyt

James Lamb

Sanghack Lee

MD

Cole MacLean

Marco

Jarrod Millman

Sanggyu Nam

Viraj Parimi

Dima Pasechnik

Richard Penney

Naresh Peshwe

Zachary Sailer

Dan Schult

Jordi Torrents

John Wegis

aparamon

aweltsch

gfyoung

md0000

mddddd

talhum

## Merged PRs¶

Update Release Notes for v2.1 (#2839)

Update release notes (#2838)

Update copyright (#2837)

Add a large clique size heuristic function (#2830)

Remove automatic processing of G.name attribute (#2829)

Add rooted product function (#2825)

Label Propagation Community Detection (#2821)

change variable names to avoid kwargs clobber (#2824)

Minimum cycle basis (#2823)

Deprecate component_subgraphs functions (#2819)

Temporarily disable sphinx doctests (#2818)

Adjust docs for graph class edge attrib assignment (#2817)

Add directed graphs support for jit_graph reading (#2753)

Arrows as a plot example. (#2801)

Fix bug in len(edges) for self-loops (#2816)

MRG: Remove

`to_pandas_dataframe`

and`from_pandas_dataframe`

(#2811)Fix Pydot tests so works with new version 1.2.4 (#2815)

MRG: Remove

`bellman_ford`

(#2812)Combine generator modules and tweak docs (#2814)

Legacy array printing for NumPy 1.14+ (#2810)

Fix rare structurally forbidden mappings bug. (#2798)

Digraph Arrows to fix #2757 (#2760)

use a generic Integral type for parameters check (#2800)

Control node-border color in draw_networkx_nodes (#2788)

Add seed keyword argument to random_layout and spring_layout (#2766)

Add Mycielski Operator (#2785)

Adds prefix_tree, dag_to_branching, and example. (#2784)

Add inverse_line_graph generator from #2241 (#2782)

Add docs for steiner_tree and metric_closure (#2783)

Steiner tree and metric closure. (#2252)

Correct docstring for weight parameter (#2781)

Switch to xcode 7.3 for osx_image in .travis.yml (#2780)

Change how sparse6 tests filenames (#2779)

Add flow based node and edge disjoint paths. (#2063)

Update geometric networks with new models (#2498)

[WIP] Graph edit distance 2361 (#2729)

max_weight_matching returns set of edges (#2774)

Avoid keyword and attribute clash (#2775)

Add threshold option to spring layout (#2776)

Fix bug in expected_degree_graph generator (#2773)

Add support for incomplete partitions in quotient_graph. (#2771)

Fix SOURCE_DATE_EPOCH ignored bug (#2735) (#2736)

Makes write_graph6 less memory-intensive. (#2299)

all_simple_paths should not return cycles. Fix issue #2762 (#2770)

Fix typo in write_gml and add test (#2769)

Fix bug and add checks for non-convergent fiedler_vector (#2681)

Dictionary comprehensions from #1700 merged conflicts (#2768)

Fix 2763: Typo

`furether`

in networkx tutorial documentation (#2764)Fix #2726: ensure add_path to add the first node (#2759)

a minor correction in docs (#2751)

Speedups for subgraph and copy methods (#2744)

fix typo in tutorial (#2746)

Expand documentation regarding strong connectivity (#2732)

Correct when we raise NetworkXNotImplemented (#2731)

removed list conversion from _triangles_and_degree_iter (#2725)

nx_shp fixes (#2721)

removed reference to create_using from union docs (#2722)

Copy graph in transitive closure algorithm. (#2718)

Fix dag_longest_path bug (#2703)

Fix for inter_community_edges (#2713)

Fix shortest_simple_paths. Issue #2427 (#2712)

Update migration_guide_from_1.x_to_2.0.rst (#2694)

mention

`doc.txt`

in`requirements/README.md`

(#2699)docs(centrality/dispersion): updating contributor email address (#2698)

Fixes bug #2503 by removing arrow labels (#2696)

Add example of spectral embedding of the grid graph (#2690)

Fix create_using of nx.from_pandas_adjacency() (#2693)

Added function for finding a k-edge-augmentation (#2572)

rm arg

`strict`

from function`networkx.drawing.nx_pydot.to_pydot`

(#2672)Fixed problem parsing graphml with nodes in groups (#2644)

Remove unused imports (#2653)

Improve subgraph node iteration (#2687)

Added Kamada-Kawai functions to Sphinx documentation (#2680)

unpacked dict to provide kwargs when creating nodes from shapefiles (#2678)

Fix typo in documentation (#2677)